Mentawai tsunami warning 'failed at the last hurdle'
[JAKARTA] Millions of pounds invested in tsunami early warning systems for Indonesia have failed to help those living in remote areas because of difficulties in quickly spreading the alarm, according to an expert.
Indonesia is now fully covered by the Indonesian Tsunami Early Warning System (InaTEWS) — a giant system made up of several smaller systems.
But, when the most recent tsunami struck on 25 October, after a magnitude 7.7 earthquake off the western Sumatra coast, it killed 431 people in the country's Mentawai Islands, raising questions about its quality.
Now the National Agency for Disaster Management (BNPB), which is charged with spreading the message about impending tsunamis, has confirmed that there were no sirens installed on the Mentawai islands.
"It is clear that there was no [way to alert people] in the Mentawais," said Costas Synolakis, director of the Tsunami Research Center at the University of Southern California, United States. "An early warning system would have sounded sirens through loudspeakers actively telling people 'evacuate now or you will die'," he told SciDev.Net.
Initial reports suggested that ocean buoys vital to the system had been vandalised but groups involved in the system insisted that it had worked, and a warning had been sent via satellite to 400 institutions in Indonesia, including the police, local emergency centres and the media, within five minutes of the quake.
"The dissemination effort is scattershot at best," said Revanche Jefrizal Kabuik, head of the Tsunami Alert Community, also known as KOGAMI, a non-governmental organisation in western Sumatra.
Installing a network of solar-powered sirens in the lower Mentawais, connected via satellite to InaTEWS centres, would cost less than US$200,000, according to Synolakis.
The alert system ought to include a public education component that includes annual evacuation drills, he added.
The head of Indonesia's Tsunami and Earthquake Centre, Fauzi, said: "Our end of the system worked according to plan".
"[BNPB] needs to work a lot harder in its efforts to work with local governments and citizens to get a better system in place on the ground. The satellites and software were the easy part. Working with people is tricky."
Dewanto, a spokesperson for the BNPB, said the organisation was aware of the lack of sirens on the Mentawai islands.
"Efforts to improve dissemination methods throughout Indonesia are ongoing. We've recently added more sirens throughout Aceh and are planning similar efforts in other parts of the country that are at risk".
InaTEWS is composed of several warning systems including the German Indonesian Tsunami Early Warning System (GITEWS) which covers an area off the Mentawai islands and was built, deployed and run in a joint partnership between Indonesia and Germany.
InaTEWS detects both earthquakes and sea-level changes and improvements are planned that will enable it to project how far tsunami waters will travel inland by 2011, said Fauzi.